1. Field of the Invention
The invention relates to an e-mail system, and more particularly to a method of issuing an interim mail address temporarily used by a user.
2. Description of the Related Art
With recent worldwide development of a communication network such as Internet, an e-mail service is used by a lot of users as a rapid and cheap communication tool, and is now indispensable for their daily life. With development of an e-mail service, electronic commercial trade using a web site spreads widely.
When a person avails him/herself of service of a web site through his/her terminal such as a cellular phone, he/she often has to show his/her mail address to a web site. However, once he/she makes his/her mail address open, he/she may receive unnecessary e-mails such as an advertisement mail, a junk mail or spam mail from the web site or from a stranger other than the web site.
If he/she changes his/her mail address, he/she could escape from such unnecessary e-mails. However, a mail address is necessary to be registered to a provider, and it is usual that one mail address is assigned to one terminal. Thus, if he/she changes his/her mail address, there is caused a problem that he/she may not receive information advantageous or necessary for him/her.
In order to solve such a problem, Japanese Patent Application Publication No. 2002-123470 has suggested a system of converting a mail address. In the system, a specific mail address is issued to each of users independently of his/her mail address. A mail address of an e-mail transmitted from a certain user and addressed to the certain user is converted into his/her specific mail address, and then, an e-mail having the specific mail address is transmitted to a destination or received by the certain user. In accordance with the system, users having registered to the system can make e-mail communication with one another through the user of his/her specific mail address, and hence, it is no longer necessary for them to make their mail addresses open to others. If one of the registered users transmits a junk mail, a spam mail and so on to other registered users, an administrator of the system can search and identify a transmitter of such mails.
However, in the above-mentioned conventional system, both of an e-mail transmitter and an e-mail receiver have to register to the system to have a specific mail address. Hence, the system is not applicable to communication between a registered person and a non-registered person. Hence, a person, even if he/she registers to the system, cannot reject receipt of unnecessary e-mails transmitted from a non-registered person, such as an advertisement mail, a junk mail or a spam mail.
Japanese Patent Application Publication No. 2002-33759 has suggested an e-mail transmission system including a terminal through which a user transmits and receives e-mails, and a server. The server includes a first device which makes an interim account temporarily used by a user, a second device which stores the interim account therein, and a third device which transmits an e-mail transmitted from the terminal, to a destination through the use of the interim account.
Japanese Patent Application Publication No. 2002-152245 has suggested a pre-paid mail system which issues an Internet mail account which can be used under limited conditions.
Japanese Patent Application Publication No. 2000-261491 has suggested an e-mail service system for cellular phones. A user can transmit an e-mail through the use of an interim mail address without using his/her own mail address.
Japanese Patent Application Publication No. 2002-183329 has suggested an e-mail service system in which a user can transmit and receive e-mails through the use of an e-mail account assigned by a provider, in a period designated by a user. When the period expires, the provider invalidates an e-mail account assigned to a user.